The surfaces of processed semiconductors become unstable when exposed to bio milieus. In particular, aqueous solutions of electrolytes may easily cause corrosion of inorganic surfaces like Si, SiO₂, SiON. Also biological materials degrade upon contact, for which the denaturation of proteins on Si/SiO2 surfaces is a well-known example. The optimization of the semiconductor interface with the bio-milieu is thus in the focus of bioelectronics in order to ensure an undisturbed charge transfer or information transfer between both.

The figure illustrates the fundamental problem of the bio-semiconductor contact, to be precise: the oxidation of a metal line that has taken a green color in the corroded segment (length of the black bar amounts to 10 µm). Such damages have to be avoided by an improved encapsulation of current-carrying components in bio-microchips.